Description The spotted ratfish, Hydrolagus colliei, is a chimaera found in the north-eastern Pacific Ocean. Often seen by divers at night in the Pacific Northwest, this harmless shark relative gets its characteristic name from a pointed rat-like tail. The ratfish lays leathery egg cases on the bottom of muddy or sandy areas which are often mistaken by divers as something inanimate. While mainly a deep-water species, it occurs at shallower depths in the northern part of its range. The generic name, Hydrolagus, comes from the Greek words "hydro", meaning water, and "lagus", meaning hare, and the specific name honors Alexander Collie, who was a ship surgeon and early naturalist. The ratfish is not typically eaten by humans and is not commercially caught.

The spotted ratfish has a very distinct appearance compared to unrelated fish species. The female is up to 38 inches (97 cm) long, much bigger than the male. These fish have a smooth and scaless skin that is a silvery-bronze color, often with sparkling shades of gold, blue, and green. The speckled white spots along their back contribute to their name. Dark edges outline both the caudal and dorsal fins, whereas, the pectoral fins have a transparent outline. The ratfish's pectoral fins are large and triangular, and extend straight out from the sides of their bodies like airplane wings. They have a venomous spine located at the leading edge of their dorsal fin. The tail of the ratfish constitutes almost half of their overall length and closely resembles a pointed rat-like tail. The body of this fish is supported by cartilage rather than bone. It has a duckbill shaped snout and a rabbit-like face. The mouth is small and contains forward directed, incisor-shaped teeth, that act as plate-like grinding teeth. One of their most mesmerizing features is their large emerald green eyes which are able to reflect light, similar to eyes of a cat.

Dimensions Up to 3'2" (96 cm).

Warning Care should be taken in handling Ratfish, as the venomous spines can cause painful wounds, and the clasping organs, on the underside, are quite sharp.